Power storage apparatus and electric vehicle

ABSTRACT

A power storage apparatus, electric device, electric vehicle, and power system are disclosed. In an example embodiment, a power storage apparatus includes a battery block comprising a plurality of battery cells and an isolating unit that enables wireless information transfer regarding battery information of the battery block.

CROSS REFERENCES TO RELATED APPLICATIONS

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2011-189562 filed in theJapan Patent Office on Aug. 31, 2011 and Japanese Priority PatentApplication JP 2012-062257 filed in the Japan Patent Office on Mar. 19,2012, the entire contents of which are hereby incorporated by reference.

BACKGROUND

The present disclosure relates to a power storage apparatus as well asto an electric vehicle that utilizes power from a power storageapparatus.

Recently, secondary batteries such as lithium-ion batteries have beenrapidly expanding to applications such as storage batteries forautomobiles and power storage apparatus in which secondary batteries arecombined with an alternative energy system such as solar cells or windturbines. In the case of using a large number of storage elements suchas unit cells (also called electrical cells or simply cells, anddesignated battery cells as appropriate in the following description) inorder to produce a large output, a configuration is adopted in which aplurality of storage modules are connected in series. A storage modulecontains battery blocks in which a plurality of battery cells (four, forexample) are connected in parallel and/or in series. A large number ofbattery blocks are enclosed in an outer case to form a storage module(also called an assembled battery).

There also exists a battery system in which a plurality of storagemodules are connected, and in which a control apparatus shared by theplurality of storage modules is provided. Each storage module includes amodule controller, with communication between the module controllers andthe control apparatus realized via a communication unit or other means.

In the case of using a plurality of battery cells, in some cases one ofthe plurality of battery cells will reach the low-voltage threshold eventhough other battery cells have not yet reached the low-voltagethreshold, due to factors such as differences in self-discharge amongthe battery cells. If the battery cells are once again charged in such astate, a problem occurs in that a battery cell may not be sufficientlycharged, and battery cell performance may not be sufficiently exhibited.

In order to compensate for such disparities among plural battery cells,battery cell balancing is typically conducted. Controlling cellbalancing involves acquiring voltage information for a plurality ofbattery cells. Japanese Unexamined Patent Application Publication No.2010-081756 describes a configuration for acquiring battery informationfrom a battery cell.

SUMMARY

In the case of connecting a plurality of storage modules in series,balancing of the modules is conducted. Since differences in powerexpenditure by a control circuit connected to each storage module are afactor that can disrupt module balance, it is preferable to not usepower from the battery pack of storage modules as the power for thecontrol circuits. Furthermore, since the voltage from a serialconnection becomes very high in the case of connecting a plurality ofstorage modules in series, isolation is desired for safety, and inaddition, circuit blocks able to operate at low voltages, such as acommunication unit and a controller, preferably operate using alow-voltage power supply.

The configuration described in Japanese Unexamined Patent ApplicationPublication No. 2010-081756 above is for acquiring battery informationfrom single battery cells, and does not make considerations for theacquisition of voltage information from individual storage modules inthe case of outputting a high voltage, such as in the case where aplurality of storage modules are connected in series.

Consequently, it is desirable to provide a power storage apparatus andan electric vehicle suitable for acquiring voltage information fromindividual storage modules in the case where a plurality of storagemodules are connected in series.

Disclosed herein is a power storage apparatus that includes a pluralityof battery units each including a single battery cell, a plurality ofbattery cells, or a plurality of battery blocks, a monitor configured toacquire the respective voltages of the batteries in the battery units, acommunication unit configured to transmit information on the voltagesfrom the monitor to a managing unit configured to manage the batteryunits, and an isolating transmission unit, disposed in an isolatingstate between the monitor and the communication unit, and configured tocommunicate the voltage information while also supplying the monitorwith power and monitor control information from the communication unit.

Also disclosed herein is a power storage apparatus that includes aplurality of battery units each including a single battery cell, aplurality of battery cells, or a plurality of battery blocks, a monitorconfigured to acquire the respective voltages of the batteries in thebattery units, a communication unit configured to transmit informationon the voltages from the monitor to a managing unit configured to managethe battery units, and an isolating transmission unit, connected in anisolating state to the output side of the communication unit, andconfigured to communicate the voltage information while also supplyingthe communication unit with power from the managing unit.

Also disclosed herein is an electric vehicle that includes a conversionapparatus configured to receive power supplied from a power storageapparatus and convert received power into drive for the vehicle, and acontrol apparatus configured to perform information processing relatedto vehicle control on the basis of information regarding the powerstorage apparatus. The power storage apparatus includes a plurality ofbattery units each including a single battery cell, a plurality ofbattery cells, or a plurality of battery blocks, a monitor configured toacquire the respective voltages of the batteries in the battery units, acommunication unit configured to transmit information on the voltagesfrom the monitor to a managing unit configured to manage the batteryunits, and an isolating transmission unit, disposed in an isolatingstate between the monitor and the communication unit, and configured tocommunicate the voltage information while also supplying the monitorwith power and monitor control information from the communication unit.

In an embodiment, a power storage apparatus includes a battery blockcomprising a plurality of battery cells and an isolating unit thatenables wireless information transfer regarding battery information ofthe battery block. In this embodiment, the isolating unit may include afirst card unit and a second card unit being configured for acontactless smart card protocol to facilitate the wireless informationtransfer, the first and second card units configured to transmit thebattery information wirelessly to each other. Additionally, theisolating unit can include a first antenna mounted on a first tracelayer of a printed circuit board and electrically connected to the firstcard unit and a second antenna mounted on a second trace layer of theprinted circuit board and electrically connected to the second cardunit, the second antenna being directionally aligned with the firstantenna to enable the wireless information transfer of batteryinformation between the first and second antennas.

In another embodiment, a power storage system includes a first storagemodule including a first battery block comprising a first plurality ofbattery cells and a first isolating unit that enables wirelessinformation transfer regarding battery information of the first batteryblock. In this other embodiment, the power storage system also includesa second storage module including a second battery block comprising asecond plurality of battery cells and a second isolating unit thatenables wireless information transfer regarding battery information ofthe second battery block. Additionally, in this embodiment, batteryinformation of the first storage module is aggregated with batteryinformation from the second storage module.

In yet another embodiment, a power storage control apparatus includes abattery block comprising a plurality of battery cells, a controllerconfigured to measure battery information of the battery block, and anisolating unit that enables wireless communication with the controllerand wirelessly transmits power to the controller.

In a further embodiment, a power storage apparatus to power a vehicleincludes a plurality of storage modules, each storage module includingat least one battery block comprising a plurality of battery cells acontroller configured to measure battery information of the at least onebattery block, and an isolating unit that enables wireless communicationwith the controller and wirelessly transmits power to the controller. Inthis embodiment, the power storage apparatus to power the vehicle alsoincludes an electrical load including an electronic transmission or amotor of a vehicle, the electrical load receiving power from anaggregate of power from the plurality of storage modules.

In a module balancing circuit of the disclosure, flyback transformers ineach module are constructed separately, thus enabling simplified wiringwithout wiring in a star pattern, unlike configurations that share amagnetic core. In the disclosure, the primary switches and the secondaryswitches of the flyback transformers can be controlled by independentcontrol pulse signals. Consequently, it becomes possible to transmitpower via a desired plurality of flyback transformers. Furthermore, bysetting the length of the on-periods during switching operation, theamounts of power to move via the flyback transformers can beindividually controlled. In other words, the amount of power to move canbe varied by lengthening the period during which a switch is switched onin accordance with the amount of power to move.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram of an exemplary storage system;

FIG. 2 is an exploded perspective view of an exemplary storage module;

FIG. 3 is a wiring diagram illustrating the wiring configuration of anexemplary storage module;

FIG. 4 is a block diagram illustrating a specific configuration of astorage system;

FIG. 5 is a block diagram of an exemplary module controller;

FIG. 6 is a block diagram illustrating a first example of aconfiguration of a storage system connecting a plurality of storagemodules;

FIG. 7 is a schematic diagram illustrating how components are packagedon a multilayer circuit board for a storage module;

FIG. 8 is a wiring diagram illustrating the circuit layout of anexemplary isolator;

FIGS. 9A and 9B are cross-section diagrams for explaining a two-layercircuit board and a four-layer circuit board;

FIGS. 10A and 10B are schematic diagrams for explaining specificexamples of a PCB antenna;

FIGS. 11A to 11C are schematic diagrams for explaining bottom balancing;

FIGS. 12A to 12C are schematic diagrams for explaining active bottomcell balancing operation;

FIGS. 13A to 13C are schematic diagrams for explaining top balancing;

FIGS. 14A to 14C are schematic diagrams for explaining active top cellbalancing operation;

FIGS. 15A and 15B are wiring diagrams of an active bottom cell balancingcircuit of the related art;

FIGS. 16A to 16D are timing charts for explaining operation of an activebottom cell balancing circuit of the related art;

FIGS. 17A and 17B are wiring diagrams of an active top cell balancingcircuit of the related art;

FIGS. 18A to 18D are timing charts for explaining operation of an activetop cell balancing circuit of the related art;

FIG. 19 is a wiring diagram of an exemplary module balancing circuit ofthe related art;

FIG. 20 is a wiring diagram of an exemplary module balancing circuit;

FIG. 21 is a wiring diagram of a first exemplary module balancingcircuit of the present disclosure;

FIG. 22 is a wiring diagram illustrating a specific example of a switch;

FIG. 23 is a wiring diagram for explaining operation of a firstexemplary module balancing circuit of the present disclosure;

FIGS. 24A to 24H are timing charts for explaining operation of a firstexemplary module balancing circuit of the present disclosure;

FIG. 25 is a wiring diagram of a second exemplary module balancingcircuit of the present disclosure;

FIG. 26 is a wiring diagram of a third exemplary module balancingcircuit of the present disclosure;

FIG. 27 is a wiring diagram of a fourth exemplary module balancingcircuit of the present disclosure;

FIG. 28 is a block diagram of a first exemplary storage system includinga module balancing circuit of the present disclosure;

FIG. 29 is a block diagram illustrating a second example of aconfiguration of a storage system connecting a plurality of storagemodules;

FIG. 30 is a wiring diagram illustrating the circuit layout of anotherexemplary isolator;

FIG. 31 is a block diagram of a second exemplary storage systemincluding a module balancing circuit of the present disclosure;

FIG. 32 is a wiring diagram for the case of applying the presentdisclosure to a cell balancing circuit;

FIG. 33 is a block diagram of a first exemplary application of a storagesystem including a module balancing circuit of the present disclosure;and

FIG. 34 is a block diagram of a second exemplary application of astorage system including a module balancing circuit of the presentdisclosure.

DETAILED DESCRIPTION

Embodiments of the present application will be described below in detailwith reference to the drawings.

Storage System

In the case of using a large number of storage elements such as batterycells in order to produce a large output, a configuration is adopted inwhich a plurality of storage units (hereinafter designated storagemodules) are connected, and in which a control apparatus shared by theplurality of storage modules is provided. Such a configuration isdesignated storage system.

A storage module is a unit combining a plurality of battery cells and acontroller. As illustrated in FIG. 1, N storage modules MOD1 to MODN areconnected in series. The storage modules MOD1 to MODN are connected toan interface bus BS via an isolator IS.

Additionally, monitors (hereinafter designated module controllers asappropriate) are connected to an overall control apparatus ICNT(hereinafter designated control box as appropriate). The control boxICNT manages charging, discharging, and wear suppression. The controlbox ICNT may be realized by a microcontroller.

A serial interface is used as the bus inside the storage modules and asthe bus BS that connects the storage modules MOD1 to MODN with thecontrol box ICNT. For the specific serial interface, an SM bus (SystemManagement Bus), CAN (Controller Area Network), or SPI (SerialPeripheral Interface) may be used. For example, an I2C bus may be used.On an I2C bus, synchronous serial communication is conducted on twosignal lines, SCL (serial clock) and a bidirectional SDA (serial data).

The module controller CNT of each storage module MOD communicates withthe control box ICNT. Namely, the control box ICNT receives informationon the internal state of each storage module, or in other words batteryinformation, with charging and discharging processes being managed foreach storage module. The control box ICNT supplies the output of the Nserially-connected storage modules (N□51.2 V) to a load. In the examplewhere N=14, the output becomes 14 □51.2 V=716.8 V.

Exemplary Storage Module

FIG. 2 is a perspective view illustrating a mechanical configuration ofa storage module MOD. The outer case of the storage module MOD includesa metallic outer case bottom 2 a and outer case top 2 b made fromprocessed sheet metal. It is preferable to use a material having highterminal conductivity and emissivity as the material for the outer casebottom 2 a and outer case top 2 b, as excellent case heat dissipationcan be obtained and temperature rises inside the case can be suppressed.For example, the material for the outer case bottom 2 a and the outercase top 2 b may be aluminum, an aluminum alloy, copper, or a copperalloy. On the back of the case are provided an external positiveterminal 3 and an external negative terminal 4 for charging anddischarging the storage module MOD.

A current breaker 5 is additionally provided on the back of the storagemodule MOD. By providing the current breaker 5, safety can be improved.Additionally, a connector 6 for communication with a control circuitdisposed inside the case 2 is provided. The control circuit is providedin order to monitor the temperature of the battery unit and controlcharging, discharging, etc. Additionally, one or more LEDs or otherdisplay elements indicating the operational state are provided on thefront of the case.

The outer case bottom 2 a of the case has a box-like structure, with theouter case top 2 b being provided so as to cover the opening.Sub-modules AS1 to AS4 are stored inside the storage space of the outercase bottom 2 a. Since the sub-modules AS1 to AS4 are secured by beingscrewed in place, for example, a plurality of bosses are formed on thefloor of the outer case bottom 2 a. The sub-modules AS1 to AS4 arepre-assembled outside of the case.

Each sub-module is an integrated combination of a plurality of batteryblocks by an insulating case that acts as a secondary storage case. Forthe sub-module case, a plastic or other molded component may be used. Inthe sub-modules AS1 to AS4, the plurality of battery blocks are storedinside cases such that the internal positive and negative terminals ofthe battery blocks are not exposed.

In a single battery block, eight cylindrical lithium-ion secondarybatteries are connected in parallel, for example. The sub-modules AS1and AS2 are integrated combinations of six battery blocks each by a casetop and a case bottom. The sub-modules AS3 and AS4 are integratedcombinations of two battery blocks each by a case top and a case bottom.Consequently, a total of 6+6+2+2=16 battery blocks are used. Thesebattery blocks are connected in series, for example.

In order to connect the battery blocks in series in each of thesub-modules AS1 to AS4, a connecting metal plate such as a bus bar isused. A bus bar is a long, thin bar of metal. A plurality of holes areformed on the bus bar for connecting with connecting metal plates, etc.leading out from the battery blocks.

As illustrated in FIG. 3, battery blocks B1 to B16 are connected inseries, with each having eight batteries connected in parallel. Thebattery blocks B1 to B16 are connected to the module controller CNT thatacts as the control apparatus for each storage module, with charging anddischarging being controlled. Charging and discharging is done via theexternal positive terminal 3 and the external negative terminal 4. Forexample, the battery blocks B1 to B6 may be included in the sub-moduleAS1, and the battery blocks B11 to B16 may be included in the sub-moduleAS2. Additionally, the battery blocks B7 and B10 may be included in thesub-module AS3, and the battery blocks B8 and B9 may be included in thesub-module AS4.

Information on the voltage between the positive and negative electrodesof each battery block, etc. is supplied to the module controller CNT viaa bus 10. The module controller CNT monitors the voltage, current, andtemperature of each battery block, and outputs the monitoring results asbattery information. For example, a single storage module MOD may output16 □3.2 V=51.2 V.

FIG. 4 illustrates a more specific connection configuration of a storagesystem. For example, four storage modules MOD1 to MOD4 may be connectedin series. In this case, the total voltage retrieved from the positiveterminal 3 (VB+) and the negative terminal 4 (VB−) is approximately 200V. The storage modules include module controllers CNT1 to CNT4 andbattery block groups BB1 to BB4, respectively. In each battery blockgroup, 16 battery blocks are connected in series, for example.

The module controllers CNT1 to CNT4 are connected via a bus, with thecommunication terminal of the module controller CNT4 connected to thecontrol box ICNT. Information on the per-module voltage, etc. from eachmodule controller is transmitted to the control box ICNT. The controlbox ICNT additionally includes a communication terminal 11 enablingexternal communication.

Exemplary Module Controller

An exemplary configuration of a module controller will be described withreference to FIG. 5. The module controller CNT is configured to detectthe voltage between the terminals of n battery blocks B1 to Bn connectedin series, as well as the voltage of each battery block. Provided is amultiplexer 15 that successively outputs the voltage between theterminals of the battery blocks B1 to Bn and the voltage of each batteryblock.

The multiplexer 15 switches channels according to a given control signaland selects one set of analog voltage data from among n sets of analogvoltage data. A set of analog voltage data selected by the multiplexer15 is supplied to an A/D converter 16 (labeled an ADC, or Analog toDigital Converter, in FIG. 5).

The A/D converter 16 converts analog voltage data supplied from themultiplexer 15 into digital voltage data. For example, analog voltagedata may be converted into 14-bit to 18-bit digital voltage data.Herein, various techniques such as successive approximation ordelta-sigma may be used as the conversion technique in the A/D converter16.

Digital voltage data from the A/D converter 16 is supplied to acommunication unit 17. The communication unit 17 is controlled by acontroller 18, and communicates with external apparatus connected viacommunication terminals 19 a and 19 b. For example, communication withthe module controller of another module may be conducted via thecommunication terminal 19 a, while communication with the control boxICNT may be conducted via the communication terminal 19 b. Additionally,the module controller CNT receives a control signal from the control boxICNT via the communication terminal 19 b. In this way, the communicationunit 17 communicates bidirectionally.

Additionally, it is configured such that the controller 18 controlsvoltage leveling across battery blocks. Such control is designated cellbalancing. For example, in the case where one battery block from amongthe plurality of battery blocks B1 to Bn has reached the low-voltagethreshold, other battery blocks still having remaining charge may exist.At the next charging, the other battery blocks with remaining charge mayquickly reach the high-voltage threshold, and charging to full chargemay be difficult. In order to avoid such imbalances, battery blocks withremaining charge are forcibly made to discharge by switching on a MOSFET(Metal-Oxide-Semiconductor Field-Effect Transistor). However, the cellbalancing technique is not limited to the passive technique discussedabove, and what are called active techniques and various othertechniques may be applied. Module balancing in this disclosure will bedescribed in detail later.

Meanwhile, the module controller CNT discussed earlier monitors thevoltage of each battery block, converts the detected voltages intodigital signals, and transmits the digital signals to the control boxICNT. In addition to voltage, the temperature of each battery block mayalso be detected, with the temperatures converted into digital data andtransmitted to the control box ICNT.

Power for the module controller CNT is supplied from the battery blocksB1 to Bn, as illustrated in FIG. 5. However, if the battery blocks B1 toBn are used as the power supply, disparities in the capacity of thebattery blocks B1 to Bn may occur among modules since the amounts ofpower consumed by the module controllers CNT are not equal to eachother, and module imbalances may occur. Given this factor, it ispreferable to not use the battery blocks B1 to Bn as the power supplyfor the module controller CNT.

In the module controller CNT illustrated in FIG. 5, the A/D converter16, the communication unit 17, and the controller 18 enclosed by theinner broken lines constitute a low-voltage power unit able to operateon a 5 V power supply, for example. In this disclosure, it is configuredsuch that power to the low-voltage power unit is supplied from thecontrol box ICNT. If power is supplied from the battery blocks B1 to Bn,there is a risk of disrupting the module balance due to differentamounts of power consumed by the module controllers CNT. In thisdisclosure, since power to the low-voltage power units of the modulecontrollers CNT is supplied from the control box ICNT, such a problemmay not occur.

First Example of Storage System According to the Disclosure

FIG. 6 illustrates a first example of a configuration in which thepresent disclosure has been applied to a storage system having n storagemodules MOD1 to MODn. The storage modules include communication unitsCOM1 to COMn, isolators ISC1 to ISCn, module controllers CNT1 to CNTn,and battery block groups BB1 to BBn, respectively. The n storage modulesare connected to a control box ICNT. For connection, communication linesL1 and L2 and a power supply line Lp are used. Bidirectionalcommunication between the control box ICNT and the storage modules MOD1to MODn is done via the communication lines L1 and L2. CAN is used asthe communication protocol, for example. Recently, CAN is being used forin-vehicle LAN.

The respective communication units COM1 to COMn in the storage modulescorrespond to the communication unit 17 in FIG. 5. Consequently, themodule controllers CNT1 to CNTn in FIG. 6 are configured to not includethe communication unit 17 compared to the configuration in FIG. 5.However, both the communication units COM1 to COMn and the communicationunit 17 may also be provided and configured to have respectivelydifferent functions. A power supply voltage such as +5 V is supplied viathe power supply line Lp as power for the low-voltage power unit in eachstorage module.

The isolators ISC1 to ISCn function to isolate the communication unitsCOM1 to COMn and the module controllers CNT1 to CNTn from each other. Inother words, the reference potential of the power supply for thecommunication units COM1 to COMn and the reference potential of thepower supply for the module controllers CNT1 to CNTn are split and madeto be independent. Additionally, the isolators ISC1 to ISCn function tosupply power supply voltage to the module controllers CNT1 to CNTn andfunction as a bidirectional communication transmission medium while inan isolated state.

As an example, take the power supply voltage for the control box ICNTand the communication units COM1 to COMn to be 0 V to +5 V. Take thepower supply voltage for the module controller CNT1 of the storagemodule MOD1 to be 0 V to +5 V, the power supply voltage for the modulecontroller CNT2 of the storage module MOD2 to be +50 V to +55 V, and thepower supply voltage for the module controller CNTn of the storagemodule MODn to be (+50 □n) V to (+50 □n)+5 V.

Isolators

The CAN standard may be used as the protocol for bidirectionalcommunication conducted via the isolators ISC1 to ISCn. Electromagneticinduction, magnetic resonance, or electromagnetic radiation techniquesmay be used as the technique for power transmission conducted via theisolators ISC1 to ISCn.

In this disclosure, contactless smart card technology is used. Withcontactless smart card technology, the antenna coil of a reader/writeris made to magnetically couple with the antenna coil of a card toconduct communication and power transmission between the reader/writerand card. Communication utilizes a technique of applying ASK (AmplitudeShift Keying) modulation to a carrier wave at a frequency of 13.56 kHz,and is conducted at a speed of 212 kbps or 424 kbps. The isolators ISC1to ISCn are made to specifications similar to the above contactlesssmart card protocol. Additionally, the isolators ISC1 to ISCn areconfigured to conduct communication and power transmission betweenantennas (coils) formed on different layers of a multilayer printedcircuit board.

As illustrated in FIG. 7, a microprocessor unit (MPU) constituting thecontrol box ICNT and a reader/writer chip 22 for the contactless smartcard protocol are mounted on a multilayer PCB 21. In addition, PCBantennas 23 and 24, a card chip 25 for the contactless smart cardprotocol, and the module controller CNT are mounted on the multilayerPCB 21.

As schematically illustrated in FIG. 8, with the contactless smart cardprotocol, a transmit signal is formed from the antenna 23 of areader/writer unit 26 to a card unit 27 with a carrier wave amplitudefrom 2 Vop to 13 Vop and an approximately 10% degree of modulation, forexample. The transmit signal is transmitted from the antenna 23 to theantenna 24 of the card unit 27. At the antenna 24, the received signalis a high-frequency signal with a carrier wave amplitude from 2 Vop to13 Vop and an approximately 10% degree of modulation, for example. Poweris formed at the card unit 27 by smoothing the received signal. Thepower consumption of the card unit 27 is significantly low.

An exemplary PCB antenna will now be described. As illustrated in FIG.9A, a four-layer PCB having four trace layers LY1 to LY4 may be used asthe multilayer PCB 21 on which antennas are formed as conductivepatterns. Alternatively, as illustrated in FIG. 9B, a two-layer PCBhaving two trace layers LY11 and LY12 may be used.

As illustrated in FIG. 10A, the primary (reader/writer) antenna 23 isformed with a coil pattern 31 a, a linear pattern 31 b, and a linearpattern 31 c. The coil pattern 31 a is formed on the fourth trace layerLY4 of the four-layer PCB, with the end at the center of the pattern 31a connected via a land and a through-hole to a land 32 a on the thirdtrace layer LY3. The linear pattern 31 b is formed between the land 32 aand the land 32 b. The land 32 b is connected to the linear pattern 31 cvia a through-hole and a land on the third trace layer LY3. The ends ofthe patterns 31 a and 31 c are connected to connectors not illustrated.

As illustrated in FIG. 10B, the secondary (card) antenna 24 is formedwith a coil pattern 41 a, a linear pattern 41 b, a linear pattern 41 c,and a linear pattern 41 d. The coil pattern 41 a, one end of which isconnected to a connector (not illustrated), is formed on the first tracelayer LY1 of the four-layer PCB. The land 42 a is connected to thelinear pattern 41 b via a through-hole and a land on the second tracelayer LY2. One end of the pattern 41 b is connected to a land on thefirst trace layer LY1 via a land 42 b and a through-hole. One end of thelinear pattern 41 c is connected to a land on the first trace layer LY1.The other end of the linear pattern 41 c is connected to a connector(not illustrated). Additionally, one end of the linear pattern 41 d isconnected to a land 42 c which is connected to the coil pattern 41 a.The other end of the linear pattern 41 d is connected to a referencepotential point.

In cases where patterns intersect, the PCB antennas are realized bydifferent trace layer patterns. Through-holes and lands are used toconnect different trace layers. As a result, extra lands 32 c and 32 dare produced on the fourth trace layer as illustrated in FIG. 10A, andan extra land 42 d is produced on the first trace layer.

It may also be configured such that jumper lines are used instead offorming the above-described patterns on other trace layers of the PCB.In other words, jumper lines may be used instead of the pattern 31 b inFIG. 10A as well as the patterns 41 b and 41 d in FIG. 10B. In thiscase, a two-layer PCB may be used, through-holes may be omitted, and theproduction of extra lands can be avoided. By not forming through-holes,it becomes possible to further increase the dielectric strength of thePCB.

The isolators in this disclosure provide insulation between the primaryantenna and the secondary antenna by means of the PCB. Consequently,with the isolators in this disclosure a DC insulation voltage of 1000 Vor more becomes possible. This furthermore has the merit of enablingbidirectional communication and power transmission, while reducingcosts.

Cell Balancing

In this disclosure, the voltage balance among the above-describedplurality of storage modules MOD1 to MODn (hereinafter simply designatedthe module balance) is controlled. In other words, the output voltagesof the storage modules are leveled by module balancing. Since eachstorage module includes many battery cells, disparities among modulesare ordinarily greater than the voltage balance among battery cellsinside the storage modules (hereinafter simply designated the cellbalance). Consequently, it is worthwhile to balance modules even if thecells within the storage modules are also being balanced.

Before describing the present disclosure, typical cell balancing will bedescribed. As illustrated in FIGS. 11A to 11C, the cell balance amongthree battery cells BT1, BT2, and BT3 will be investigated. First,assume that all battery cells are fully charged, as illustrated in FIG.11A. Next, assume that the battery cells have discharged and disparitiesin the discharge amounts have occurred, and that the voltage of thebattery cell BT1 has reached the low-voltage threshold indicated by thebroken line, as illustrated in FIG. 11B. Due to the disparities amongthe battery cells, the other battery cells BT2 and BT3 have not yetreached the low-voltage threshold. Differences in self-discharge ratesmay be the cause of the disparities in the discharge amounts among thebattery cells, for example.

If charging commences in this state, the battery cell BT2, which had themost charge remaining at the time the voltage of the battery cell BT1reached the low-voltage threshold, may reach full charge first. At thispoint, the battery cell BT1 may not have been charged to full charge, asillustrated in FIG. 11C. Consequently, the amount that can be dischargedfrom a full charge may decrease from the discharge amount C1 to thedischarge amount C2.

In order to solve this problem, as illustrated in FIGS. 12A and 12B, theremaining charges are nearly equalized by transferring power from thebattery cell BT2, which had the most charge remaining (highestpotential) at the time the battery cell BT1 reached the low-voltagethreshold, to the battery cell BT1, which had the least charge (lowestpotential). By subsequently charging the battery cells BT1, BT2, andBT3, the three battery cells can be charged to nearly the full chargevoltage. In practice, the process is repeated multiple times.

Such control is designated active bottom cell balancing. With bottomcell balancing, decreases in the dischargeable amount can be prevented.Passive bottom cell balancing designates a technique in which, given thestate illustrated in FIG. 12A, the battery cells BT2 and BT3 aredischarged to match the potential of the battery cell BT1 with thelowest potential. Compared to passive techniques, active techniques canutilize charge more effectively and are thus preferable.

Active balancing will not be described with reference to FIGS. 13A to13C and 14A to 14C. First, assume that all battery cells have been fullycharged, as illustrated in FIG. 13A. Next, assume that the battery cellsare discharged, as illustrated in FIG. 13B.

If charging subsequently commences, the voltage of the battery cell BT2reaches the high-voltage threshold first, as illustrated in FIG. 13C. Atthis point, the voltages of the battery cells BT1 and BT3 have notreached the high-voltage threshold. Consequently, the charged amountdecreases as indicated by C12 with respect to the charged amount C11(FIG. 13A).

In order to solve this problem, as illustrated in FIGS. 14A and 14B, theremaining charges are nearly equalized by transferring power from thebattery cell BT2, which had the most charge (highest potential) at thetime the battery cell BT2 reached the high-voltage threshold, to thebattery cell BT1, which had the least charge (lowest potential). Bysubsequently charging the battery cells BT1, BT2, and BT3, the threebattery cells can be charged to nearly the full charge voltage. Inpractice, the process is repeated multiple times.

Such control is designated active top cell balancing. With top cellbalancing, decreases in the chargeable amount can be prevented. Passivetop cell balancing designates a technique in which, given the stateillustrated in FIG. 14A, the battery cells BT2 and BT3 are discharged tomatch the potential of the battery cell BT1 with the lowest potential.Compared to passive techniques, active techniques can utilize chargemore effectively and are thus preferable.

Cell Balancing Circuit of the Related Art

An exemplary active bottom cell balancing circuit of the related artthat uses a flyback transformer will now be described with reference toFIGS. 15A to 15B and 16A to 16D. The cathode and anode of each batterycell are respectively connected to both ends of primary coils W1 to W6.The cathode and anode of six battery cells BT1 to BT6 connected inseries are connected to both ends of a secondary coil W0. Additionally,a common magnetic core M is provided. Additionally, the secondary coilW0 is connected in series to a secondary switch S0, and the primarycoils W1 to W6 are respectively connected in series to primary switchesS1 to S6. The switches S0 to S6 are realized with MOSFETs(Metal-Oxide-Semiconductor Field-Effect Transistor), for example.

FIGS. 16A to 16D are timing charts for operation of the active bottomcell balancing circuit illustrated in FIGS. 15A and 15B. As an example,the respective voltages of the battery cells BT1 to BT6 are detected bya monitor not illustrated, and the voltage of the battery cell BT2 isthe lowest. In this case, power is moved to the battery cell BT2 fromthe other battery cells. First, the switch S0 is switched on asillustrated in FIGS. 15A and 16A, and a current I1 as illustrated inFIG. 16C flows in the coil W0, magnetizing the magnetic core M.

Next, the primary switch S2 connected in series to the coil W2 isswitched on as illustrated in FIGS. 15B and 16B, while in addition, thesecondary switch S0 is switched off, as illustrated in FIG. 16A.Electromagnetic energy in the magnetic core M is released and a currentI2 flows through the primary coil W2, as illustrated in FIG. 16D. Thiscurrent I2 flows into the battery cell BT2, charging the battery cellBT2.

After that, the primary switch S2 is switched off, as illustrated inFIG. 16B. Additionally, a pause is subsequently held for a given amountof time. Operation is repeated, with the above on-period of thesecondary switch S0, the on-period of the primary switch S2, and thepause period making up the cycle period.

An exemplary active top cell balancing circuit of the related art willnow be described with reference to FIGS. 17A to 17B and 18A to 18D. Thecathode and anode of each battery cell are respectively connected toboth ends of primary coils W1 to W6. The cathode and anode of sixbattery cells BT1 to BT6 connected in series are connected to both endsof a secondary coil W0. Additionally, a common magnetic core M isprovided. Additionally, the secondary coil W0 is connected in series toa secondary switch S0, and the primary coils W1 to W6 are respectivelyconnected in series to primary switches S1 to S6. The switches S0 to S6are realized with MOSFETs, for example.

FIGS. 18A to 18D are timing charts for operation of the active top cellbalancing circuit illustrated in FIGS. 17A and 17B. As an example, therespective voltages of the battery cells BT1 to BT6 are detected by amonitor not illustrated, and the voltage of the battery cell BT5 is thehighest. In this case, power is moved to the battery cell BT5 from theother battery cells. First, the switch S5 is switched on as illustratedin FIGS. 17A and 18B, and a current I1 flows through the coil W5 asillustrated in FIG. 18D, magnetizing the magnetic core M.

Next, the secondary switch S0 is switched on as illustrated in FIGS. 17Band 18A, while in addition, the primary switch S5 is switched off, asillustrated in FIG. 18B. Due to the electromagnetic energy in themagnetic core M, a current I2 flows through the secondary coil W0, asillustrated in FIG. 18C. This current I2 flows into the battery cellsBT1 to BT6 connected in series, and power is distributed among thebattery cells.

After that, the secondary switch S0 is switched off, as illustrated inFIG. 18A. Additionally, a pause is subsequently held for a given amountof time. Operation is repeated, with the above on-period of the primaryswitch S5, the on-period of the secondary switch S0, and the pauseperiod making up the cycle period.

Module Balancing Circuit

The balancing circuit of the related art discussed above relates tobattery cells, and problems occur when applied to balance among themodules described with reference to FIGS. 1 to 6. Herein, module balancerefers to the voltage balance of battery units that include a pluralityof battery cells or battery blocks inside respective storage modules.Ordinarily, imbalances among modules take greater values versusimbalances within modules. Although it is possible to resolve imbalancesamong modules as a result of balancing each storage module, the processtakes more time. However, module balancing and the cell balancing of therelated art discussed above may also be used in conjunction. As anexample, in this case inter-module balancing is conducted first and thenintra-module balancing is conducted.

FIG. 19 illustrates a configuration in which a cell balancing circuit ofthe related art has been applied as-is to an active module balancingcircuit. Balancing is conducted among 14 modules, for example. Batteryblock groups BB1 to BB14 are connected in series. Each battery blockgroup is configured with eight battery cells connected in parallel andwith 16 parallel connections of eight battery cells each (batteryblocks) connected in series (referred to as an 8P16S configuration). Asingle battery block group produces a voltage of 3.2 V □16=51.2 V.Consequently, 14 battery block groups BB1 to BB14 connected in seriesproduce a voltage of 51.2 V □14=716.8 V.

The cathode and anode of the 14 battery block groups connected in seriesare connected to both ends of a secondary coil W0. Additionally, acommon magnetic core M is provided. A secondary switch S0 is connectedin series to the secondary coil W0, and primary switches S1 to S14 arerespectively connected in series to primary coils W1 to W14. Theswitches S0 to S14 are realized with MOSFETs, for example.

Active bottom cell balancing operation with the configuration in FIG. 19involves switching on the switch S0, magnetizing the magnetic core M dueto the current that flows through the secondary coil W0. Next, theprimary switch is switched on for the storage module with the lowestvoltage, and the battery block group of the corresponding storage moduleis charged by the electromagnetic energy imparted to its primary coil.As an example, in the case where the voltage of the battery block groupBB2 is 32.0 V and the voltage of the other battery block groups is 32.6V, after the secondary switch S0 has been switched on for a given amountof time, the switch S0 is switched off while the primary switch S2 ofthe battery block group BB2 is switched on. The battery block group BB2is charged by the current that flows through the primary coil W2.

Active top cell balancing operation with the configuration in FIG. 19involves switching on the switch connected to the primary coil of thebattery block group with the highest voltage. Next, that switch isswitched off while the switch S0 is switched on. Current flows throughthe secondary coil W0, and the battery block groups BB1 to BB14 arecharged. As an example, in the case where the voltage of the batteryblock group BB2 is 56.5 V and the voltage of the other battery blockgroups is 55.9 V, after the primary switch S2 has been switched on for agiven amount of time, the switch S2 is switched off while the secondaryswitch S0 is switched on. The battery block groups BB1 to BB14 arecharged by the current that flows through the secondary coil W0.

Since the magnetic core M of the transformer is shared in theconfiguration in FIG. 19, it is difficult to configure it such that aplurality of storage modules, such as 14, are stored in separate cases.In such cases, a transformer apparatus is configured such that atransformer unit including a magnetic core, a coil, and a switch isstored in a separate case from the 14 storage modules, with the 14storage modules being connected in a star pattern centered about thetransformer apparatus. Such a star pattern configuration is problematicin that the star pattern wiring becomes complex if there are manystorage modules.

Problems with Module Balancing Circuit of the Related Art

In the configuration in FIG. 19, a voltage of 716.8 V is applied to theseries circuit of the secondary coil W0 and the switch S0 by the 14battery block groups connected in series. When used in practice, apreferable withstand voltage is taken to be approximately three timesthe applied voltage. Thus, the withstand voltage becomes 2000 V for theFETs or other semiconductor switch element constituting the switch S0.The configuration in FIG. 19, which includes semiconductor switchelements with such withstand voltages, is difficult to realize.

As illustrated in FIG. 20, the magnetic core M may be split into 14magnetic cores M1 to M14, and the secondary coil W0 may be split into 14secondary coils W01 to W014. In so doing, the 14 storage modules can besplit up and stored in cases. In the configuration in FIG. 20, a voltageof 716.8 V is respectively applied to the primary switches S01 to S014.However, with the configuration in FIG. 20, it is possible to constructflyback transformers separately and respectively connect the primary andsecondary switches to the coils for independent control of switchingoperation. Consequently, as discussed later, it becomes possible tocontrol the parallel retrieval of power from a plurality of batteryblock groups as well as the parallel supply of power to a plurality ofbattery block groups. Moreover, the amount of power can be controlled bycontrolling the length of the on-periods during switching operation.

Module Balancing Circuit According to Disclosure

As illustrated in FIG. 21, in this disclosure, a flyback transformer T1includes a primary coil W1, a secondary coil W01, and a magnetic coreM1. A switch S1 is connected in series to the primary coil W1, and aswitch S01 is connected in series to the secondary coil W01. Flybacktransformers T2 to T14 similarly include primary coils W2 to W14,secondary coils W02 to W014, and magnetic cores M2 to M14. Switches S2to S14 are connected in series to the primary coils W2 to W14. SwitchesS02 to S014 are connected in series to the secondary coils W02 to W14.

The series circuit of the primary coil W1 and the switch S1 in theflyback transformer T1 is connected to the positive and negative ends ofa battery block group BB1 in a storage module. The other respectiveseries circuits of the primary coils W2 to W14 and the switches S2 toS14 are connected to the positive and negative ends of the battery blockgroups BB2 to BB14 in storage modules.

A storage element 51 is provided, and a common power supply voltage CVis produced by the storage element 51. The common power supply voltageCV is taken to be a lower voltage than the total voltage 716.8 V of thebattery block groups connected in series, and is preferably set to avoltage that is approximately ⅓ of the withstand voltage of thesecondary switches or less. For example, the common power supply voltageCV may be set to a value approximately equal to the unit voltage (51.2V) of a battery block group. By controlling the total dischargingcurrent and the total charging current, the common power supply voltageCV is controlled at a desired voltage without overvoltage orundervoltage.

The storage element 51 is a battery, capacitor, etc. Due to the storageelement 51, one common power supply line CL+ is taken to be at thecommon power supply voltage CV, while another common power supply lineCL− is taken to be a 0V. The other common power supply line CL− is takento be a separate power supply not connected to the power supply (V−) forthe battery block groups of the plurality of storage modules connectedin series. However, the common power supply line CL− may be connected tothe power supply V−. One end of each of the split secondary coils W01 toW014 is connected to the common power supply line CL+, while the otherend of each of split secondary coils W01 to W014 is connected to thecommon power supply line CL− via the switches S01 to S014.

The switches S1 to S14 as well as the switches S01 to S014 are realizedwith MOSFETs, for example. As illustrated in FIG. 22, the switch S01 ofthe flyback transformer T1 for example includes a MOSFET Q01 with adiode D01 connected between its drain and source, while the switch S1includes a MOSFET Q1 with a diode D1 connected between its drain andsource. Switching on and off is controlled by a control signal from thecontroller of the control box ICNT. The control box ICNT receivesinformation on voltage monitoring results from the module controller CNTin each storage module, and generates a control signal (pulse signal).However, other semiconductor switch elements besides MOSFETs may also beused, such as IGBTs (Insulated Gate Bipolar Transistors). However, witha switch (including a MOSFET and a diode connected between its drain andsource), current automatically flows through the diode in response tocurrent flowing in the source-to-drain direction, even without a controlsignal (automatic switch-on).

The common power supply voltage CV is applied to the series circuits ofthe secondary coils W01 to W014 and the switches S01 to S014. Forexample, by setting the common power supply voltage CV to a voltagesimilar to the voltage applied to the primary coils and switches (51.2V), the withstand voltage of the secondary switches S01 to S014 can betaken to be approximately 154 V. Such a withstand voltage is not aparticularly high value for the semiconductor switch constituting thesecondary switches S01 to S014, making it easier to construct a modulebalancing circuit.

In each of the flyback transformers T1 to T14, the turns ratio ofprimary coil versus secondary coil is not limited to one, but the phaseis taken to be inverted between primary and secondary. Furthermore, theflyback transformers T1 to T14 are able to bidirectionally transmitpower. Consequently, the labeling of “primary” and “secondary” is forthe sake of convenience, and it is possible to transmit power both fromprimary to secondary as well as from secondary to primary.

Taking the flyback transformer T1 as an example, if the switch S1 isswitched on from a state where the switches S1 and S01 are off, currentflows through the coil W1, magnetizing the magnetic core M1. During theperiod in which the switch S1 is on, a current that increases with timeflows through the coil W1. Next, if the switch S1 is switched off andthe switch S01 is switched on, current flows into the coil W01 via theswitch S01, since the magnetic core is magnetized. This current is acurrent that decreases with time. Operation of the other flybacktransformers is similar. The flyback transformers function as coupledinductors.

Active bottom cell balancing operation with the configuration in FIG. 21involves controlling the primary switches to move power from the batteryblock group with the highest voltage to the storage element 51, andadditionally controlling the secondary switches to move power to thebattery block group of the storage module with the lowest voltage. Inthis way, a module balancing circuit according to the disclosure movespower in two stages via bidirectional flyback transformers.

As an example, operation will be described for the case where thevoltage of the battery block group BB3 is the highest at 32.6 V, whilethe voltage of the battery block group BB2 is the lowest at 32.0 V.First, the switch S3 is switched on, and current flows into the primarycoil W3 of the flyback transformer T3 with the battery block group BB3acting as the power supply. Next, the switch S3 is switched off and theswitch S03 is switched on. Due to the electromagnetic energy, currentflows through the secondary coil W03, charging the storage element 51.

Next, the switch S03 is switched off while the switch S02 is switchedon. Due to the storage element 51, current flows through the secondarycoil W02 of the flyback transformer T2. Next, the switch S02 is switchedoff while the switch S2 is switched on. The battery block group BB2 ischarged by the current that flows through the primary coil W2. In sodoing, active bottom cell balancing operation is achieved.

Active top cell balancing operation with the configuration in FIG. 21involves controlling the primary switches to move power from the batteryblock group with the highest voltage to the storage element 51, andadditionally controlling the secondary switches to move power to thebattery block group of the storage module with the lowest voltage. Inthis way, a module balancing circuit according to the disclosure movespower in two stages via bidirectional flyback transformers.

As an example, operation will be described for the case where thevoltage of the battery block group BB3 is the highest at 56.5 V, whilethe voltage of the battery block group BB2 is the lowest at 55.9 V.First, the switch S3 of the flyback transformer T3 is switched on, andcurrent flows into the primary coil W3 with the battery block group BB3acting as the power supply. Next, the switch S3 is switched off and theswitch S03 is switched on. Due to the electromagnetic energy, currentflows through the secondary coil W03, and the storage element 51 ischarged.

Next, the switch S03 is switched off while the switch S02 of the flybacktransformer T2 is switched on. Due to the storage element 51, currentflows through the secondary coil W02. Next, the switch S02 is switchedoff while the switch S2 is switched on. The battery block group BB2 ischarged by the current that flows through the primary coil W2. In sodoing, active top cell balancing operation is achieved.

Active top cell balancing operation will now be described in furtherdetail with reference to FIGS. 23 and 24A to 24H. As illustrated in FIG.23, a current that flows through the coil W3 of the flyback transformerT3 is labeled i1, while a current that flows through the coil W03 islabeled i2. The currents i1 and i2 are in antiphase. A current thatflows through the coil W02 of the flyback transformer T2 is labeled i3,while a current that flows through the coil W2 is labeled i4. Thecurrents i3 and i4 are in antiphase. Furthermore, assume that thestorage element 51 is fully charged when operation commences.

As illustrated in the timing chart in FIG. 24, power transmission viathe flyback transformer T3 and power transmission via the flybacktransformer T2 are conducted in parallel. First, the switches S3 and S02are switched on for the same period, as illustrated in FIGS. 24A and24C. Switching on the switch S3 causes a gradually increasing current itto flow through the coil W3, as illustrated in FIG. 24E. Switching onthe switch S02 causes a gradually increasing current i3 to flow throughthe coil W02, as illustrated in FIG. 24G. The current i3 flows in adischarge direction to the storage element 51.

Next, the switches S3 and S02 are switched off, and the switches S03 andS2 are switched on for the same period, as illustrated in FIGS. 24B and24D. Switching on the switch S03 causes a gradually decreasing currenti2 to flow through the coil W03, as illustrated in FIG. 24F. The currenti2 flows in a charging direction to the storage element 51. Due to thecharging of the storage element 51 by the current i2, power is movedfrom the battery block group BB3 to the storage element 51.

Switching on the switch S2 causes a gradually decreasing current i4 toflow through the coil W2, as illustrated in FIG. 24H. The current i4flows in a charging direction to the battery block group BB2. Due to thecharging by the current i4, power in the storage element 51 is moved tothe battery block group BB2. Note that in actual power transmission, itis configured such that power is moved a little bit at a time bymultiple switching operations rather than a single switching operation.Furthermore, the amount of power to move can be set to a desired amountby applying pulse-width modulation to a pulse signal for a switch tocontrol the switch's on-period. Also, although the switches S3 and S02are depicted in a synchronized form in FIGS. 24A and 24C, in practice anasynchronous relationship may be acceptable by allowing a given range inthe common power supply voltage CV.

Modification of Module Balancing Circuit According to Disclosure

In the above-described module balancing circuit according to thedisclosure, it is configured such that power retrieved via a singleflyback transformer is moved via a single flyback transformer. However,power may also be retrieved via a plurality of flyback transformers. Forexample, it may be configured such that power is retrieved from both thestorage module with the largest voltage and the storage module with thesecond-largest voltage. Furthermore, it may also be configured such thatretrieved power is moved via a plurality of flyback transformers. Forexample, it may be configured such that power is supplied to both thestorage module with the lowest voltage and the storage module with thesecond-smallest voltage. For example, with the configuration in FIG. 21discussed above, power may be retrieved with a small current via theflyback transformer T14, while at the same time retrieving power with alarge current via the flyback transformer T3. Additionally, it may beconfigured such that power is respectively supplied with medium currentsvia the flyback transformers T1 and T2, contemporaneously with the powerretrieval.

As illustrated in FIG. 25, capacitors C1 to C14 are inserted between thecommon power supply line CL+ and the common power supply line CL− on thesecondary side in each of the flyback transformers T1 to T14 of thestorage modules. By reducing high-frequency components with thecapacitors C1 to C14, voltages produced on the common power supply linesCL+ and CL− can be output as DC (Direct Current) power. It may also beconfigured such that this DC power is supplied as the power supply forthe control box ICNT.

Furthermore, as illustrated in FIG. 26, it may be configured such that acommon flyback transformer Tx is provided for all storage modules. Theflyback transformer Tx includes a primary coil Wy, a secondary coil Wx,and a magnetic core Tx. The coil Wx is connected in series to a switchSx. The coil Wy is connected in series to a switch Sy. One end of thesecondary coil Wx in the flyback transformer Tx is connected to aterminal 52, while the other end is connected to a 0V line via theswitch Sx. The terminal 52 is connected to the common power supplyvoltage CV terminal.

One end of the primary coil Wy is connected to the cathode (V+) of aseries connection of battery block groups BB1 to BB14 in a plurality ofstorage modules, such as 14. The other end of the primary coil Wy isconnected to the anode (V−) of the series connection of battery blockgroups BB1 to BB14. Flyback transformers T1 to T14 and a storage element51 are connected to the battery block groups BB1 to BB14 similarly tothe configuration in FIG. 21, and module balancing like that discussedearlier is conducted.

According to the configuration in FIG. 26, power can be supplied to thebattery block groups of all storage modules at once via the flybacktransformer Tx, enabling increased variation in module balancingoperation.

Furthermore, in this disclosure, it is possible to use a powertransmission apparatus based on an electromagnetic coupling technique,such as a forward converter or RCC (Ringing Choke Converter) technique,rather than a flyback converter technique.

FIG. 27 illustrates an application of the disclosure, in which thestorage modules MOD1 to MOD14 (the configuration illustrated in FIG. 21)are connected to another storage system that includes storage modulesMOD101 to MOD104. It is possible to connect the common power supplylines CL+ and CL− to the other storage system if the common power supplyvoltages CV have an equivalent relationship between the two storagesystems. In other words, it is easy to increase the number of connectedstorage modules.

FIG. 28 illustrates an exemplary overall configuration of a storagesystem that includes storage modules, such as storage modules MOD1 andMOD2. Control pulses are supplied from pulse generators 53 to theprimary switches (MOSFETs) S1 and S2 of the flyback transformers T1 andT2 in the module balancing circuit discussed earlier. The pulsegenerators 53 generate control pulses in response to control signalsfrom the module controllers CNT1 and CNT2. For example, the pulsegenerators 53 may output PWM control pulses. Control pulses are suppliedfrom MCUs (Microcontroller Units) in communication units COM1 and COM2to the secondary switches (MOSFETs) S01 and S02 of the flybacktransformers T1 and T2.

The control box ICNT determines a module balancing sequence fromper-module voltage information. Any module balancing charging ordischarging is individually relayed to the MCUs in the communicationunits COM1 and COM2 of the respective modules. The MCUs respectivelysupply the secondary side of the flyback transformers with controlsignals directly, or transmit control signals to the primary side of theflyback transformers by isolated communication via isolators ISC.

Control signals are supplied from separate circuit blocks for theprimary and secondary sides because of differences in the control signallevels. Also, in parallel with the operation discussed earlier, thecontrol box ICNT measures the voltage between the power supply lines CL+and CL− supplying the common power supply voltage CV, and appliesoverall module balancing control such that the common power supplyvoltage CV becomes a desired voltage.

Advantages of Power Storage Apparatus According to Disclosure

In a module balancing circuit of the disclosure, the flybacktransformers in each module are constructed separately, thus enablingsimplified wiring without wiring in a star pattern, unlikeconfigurations that share a magnetic core.

In a module balancing circuit of the disclosure, the voltage at eitherend of a battery block group in each storage module is applied to theprimary coil and switch of a flyback transformer, while a common powersupply voltage CV is applied to the secondary coil and switch. Thecommon power supply voltage CV is taken to be a value equivalent to thevoltage at either end of a battery block group in each storage module,for example. Consequently, there is an advantage in that the voltage ofall storage modules connected in series is not applied to the coils andswitches, and elements with low withstand voltages can be used for thecoils and switches.

In this disclosure, the primary switches S1 to S14 and the secondaryswitches S01 to S014 of the flyback transformers can be controlled byindependent control pulse signals. Consequently, it becomes possible totransmit power via a desired plurality of flyback transformers.Furthermore, by setting the length of the on-periods during switchingoperation, the amounts of power to move via the flyback transformers canbe individually controlled. In other words, the amount of power to movecan be varied by lengthening the period during which a switch isswitched on in accordance with the amount of power to move.

Additionally, since a large current flows between the output terminalsV+ and V− of the plurality of storage modules, a comparatively largeamount of noise may be easily produced. However, since the common powersupply voltage CV is isolated from the output terminals V+ and V−, theeffects of noise due to fluctuations in the load current can belessened.

A common power supply voltage CV with little influence from noise can beused as the power supply for the control box ICNT. For example, thevalue of the common power supply voltage CV may be taken to be a valueequivalent to the power supply voltage of the controller (such as +5 Vor +12 V). When using the common power supply voltage CV as the powersupply for the control box ICNT, the power supply for the control boxICNT can be made resilient to voltage fluctuations in the storagemodules.

Second Example of Storage System According to the Disclosure

In the first example of a storage system discussed above, isolators ISC1to ISCn are disposed between the communication units COM1 to COMn andthe module controllers CNT1 to CNTn, as illustrated in FIG. 6. However,a second example of a storage system is configured such that theisolators ISC1 to ISCn are disposed between the communication units COM1to COMn and the control box ICNT, as illustrated in FIG. 29. Theisolators ISC1 to ISCn and the control box ICNT are connected bycommunication lines L1 and L2, and by a power line Lp. An interface suchas SPI or CAN is used as the communication interface. Although disposedinside the storage modules MOD1 to MODn in FIG. 29, the isolators ISC1to ISCn may also be disposed externally to the modules.

Similarly to the first example discussed above, the isolators ISC1 toISCn function to isolate the communication units COM1 to COMn and thecontrol box ICNT from each other, supply power supply voltage to thecommunication units COM1 to COMn, and function as a transmission mediumfor bidirectional communication. The CAN standard, for example, may beused as the protocol for bidirectional communication conducted via theisolators ISC1 to ISCn. Electromagnetic induction, magnetic resonance,or electromagnetic radiation techniques may be used as the technique forpower transmission conducted via the isolators ISC1 to ISCn.

Besides an isolator configuration that uses contactless smart cardtechnology as in the first example discussed above, a photocouplerconfiguration may also be used, in which changes in light from aphotodiode 61 are converted to changes in voltage by a phototransistor62, as illustrated in FIG. 30A. The photocoupler is used for datatransmission. Additionally, a device that conducts wirelesscommunication based on short-range wireless technology may be used, thedevice including a transmitter device 71 and a receiver device 72, asillustrated in FIG. 30B. Specifically, a technology such as Bluetooth(registered trademark), USB, ZigBee, or NFC may be used. Wirelesstechnologies other than short-range wireless technology may also beused.

Bluetooth (registered trademark) is a short-range wireless technologywith a maximum communication range of 100 meters, using the 2.4 GHzfrequency band. UWB (Ultra-Wideband) is able to use a very largebandwidth (3.1 GHz to 10.6 GHz) to communicate up to a maximum of 480Mbps over a distance of approximately 10 meters. ZigBee is a short-rangewireless technology being standardized by the ZigBee Alliance. ZigBeeuses the 2.4 GHz, 902 to 928 MHz, and 868 to 870 MHz frequency bands,with a maximum communication range from 9 to 69 meters. NFC (Near FieldCommunication) is a short-range wireless technology in the 13.56 MHzband. NFC standardizes the wireless interface portion of contactlesssmart card technologies from multiple standards, creatingcross-compatibility among contactless smart cards. NFC has beenstandardized in two stages, and two standards, Type A and Type B, exist.Furthermore, a configuration compatible with a plurality ofcommunication protocols may also be included.

In this disclosure, the isolators ISC1 to ISCn transmit power inaddition to communicating data. In order to transmit power, a wirelesspower transmission protocol between a power transmitter device 73 and apower receiver device 74 utilizing for example magnetic resonance isused, as illustrated in FIG. 30C. A high-frequency signal from ahigh-frequency power supply is supplied to the power transmitter device73 via a matching circuit. Connected to the power receiver device 74 area matching circuit and a rectifier circuit.

FIG. 31 illustrates an exemplary overall configuration of a secondexample of a storage system that includes storage modules, such asstorage modules MOD1 and MOD2. Battery block groups BB1 and BB2 arerespectively connected to module balancing circuits. Each modulebalancing circuit is supplied with a control signal from modulecontrollers CNT1 and CNT2, and a control signal from MCUs(Microcontroller Units) in the communication units COM1 and COM2. Themodule balancing circuits are controlled similarly as in theconfiguration illustrated in FIG. 28.

A power supply line and a communication line from the control box ICNTare respectively illustrated as single lines. A connection between thecontrol box ICNT and the communication units COM1 and COM2 is formed viathe isolators ISC1 and ISC2, and power is supplied from the control boxICNT to the communication units COM1 and COM2 via the isolators ISC1 andISC2. The second example of a storage system according to the disclosurelikewise exhibits advantages similar to those of the first examplediscussed above.

Although the foregoing description is for the case in which thedisclosure is applied to a module balancing circuit, the disclosure mayalso be applied to cell balancing. In other words, by respectivelysubstituting the battery block groups BB1 to BB14 with battery cells inthe configuration illustrated in FIG. 21 discussed earlier, a cellbalancing circuit can be realized. Advantages similar to those of theforegoing module balancing circuit are still obtained in the case ofapplying the disclosure to a cell balancing circuit.

The disclosure can be applied to a cell balancing circuit as illustratedby the typical configuration in FIG. 32. In FIG. 32, n battery cells B11to Bin are connected in series, and in addition, there are m sets of thebattery cells connected in series, with the sets connected in parallel.The primary coils of flyback transformers T11 to T1 n and Tm1 to Tmn areconnected in parallel to each battery cell, and primary switches S11 toS1 n and Sm1 to Smn are connected in series to the primary coils. Oneend of the secondary coil of each flyback transformer is connected tothe power supply line CL+ of a common power supply voltage CV, while theother end of the secondary coil is connected in series to the powersupply line CL− of the common power supply voltage CV via respectivesecondary switches S011 to S01 n and S0 m 1 to S0 mn.

Furthermore, the disclosure may take configurations like the following.In an embodiment, a power storage apparatus includes a battery blockcomprising a plurality of battery cells and an isolating unit thatenables wireless information transfer regarding battery information ofthe battery block. In this embodiment, the battery information includesone of a voltage value, a current value, or a temperature value. In thisembodiment the isolating unit includes a first card unit and a secondcard unit being configured for a contactless smart card protocol tofacilitate the wireless information transfer, the first and second cardunits configured to transmit the battery information wirelessly to eachother.

In an embodiment, the isolating unit includes a first antenna mounted ona first trace layer of a printed circuit board and electricallyconnected to the first card unit and a second antenna mounted on asecond trace layer of the printed circuit board and electricallyconnected to the second card unit, the second antenna beingdirectionally aligned with the first antenna to enable the wirelessinformation transfer of battery information between the first and secondantennas. In an embodiment, the contactless smart cart protocol includesAmplitude Shift Keying (ASK) modulation with a carrier wave frequency ofabout 13.56 MHz at a speed between 212 kbps and 424 kbps, the carrierwave having an amplitude between 2 volts to 13 volts with a 10% degreeof modulation.

In an embodiment, the isolating unit enables wireless communication withthe battery block via non-contact smart card technology by applyingAmplitude Shift Keying (ASK) modulation to a carrier wave frequencybetween 10 MHz and 20 MHz. In an embodiment, the isolating unit includesa controller area network (CAN) communication protocol to facilitate thewireless information transfer. In an embodiment, wireless informationtransfer includes transfer via at least one of electromagneticinduction, magnetic resonance, or electromagnetic radiation.

In an embodiment, the power storage apparatus further includes acontroller configured to measure battery information of the batteryblock. In an embodiment, the isolating unit enables wireless powertransfer to power the controller. In an embodiment, the isolating unitincludes a first antenna mounted on a first trace layer of a printedcircuit board and a second antenna mounted on a second trace layer ofthe printed circuit board, the second antenna being directionallyaligned with the first antenna to enable the wireless informationtransfer of battery information between the first and second antennas.

In an embodiment, the first and second antennas are shaped in linearcoil patterns. In an embodiment, the first and second antennas aremagnetically coupled through the printed circuit board. In anembodiment, the second antenna is connected in parallel to a resistorand a capacitor to filter the received battery information. In anembodiment, the first trace layer is separated from the second tracelayer by at least one insulation layer of the printed circuit board.

In another embodiment, a power storage system includes a first storagemodule including a first battery block comprising a first plurality ofbattery cells and a first isolating unit that enables wirelessinformation transfer regarding battery information of the first batteryblock and a second storage module. In this other embodiment, the powerstorage system also includes a second battery block comprising a secondplurality of battery cells and a second isolating unit that enableswireless information transfer regarding battery information of thesecond battery block. In this other embodiment, battery information ofthe first storage module is aggregated with battery information from thesecond storage module.

In an embodiment, the battery information includes one of a voltagevalue, a current value, or a temperature value. In an embodiment, eachof the first and second isolating units includes a first card unit and asecond card unit being configured for a contactless smart card protocolto facilitate the wireless information transfer, the first and secondcard units configured to transmit the battery information wirelessly toeach other.

In an embodiment, the power storage system further includes a managingunit configured to aggregate the battery information of the firststorage module with the battery information from the second storagemodule. In an embodiment, the power storage system further includes afirst communication unit included within the first storage moduleconfigured to transmit battery information of the first battery block tothe managing unit, a first controller included within the first storagemodule configured to measure the battery information of the firstbattery block, a second communication unit included within the secondstorage module configured to transmit battery information of the secondbattery block to the managing unit, and a second controller includedwithin the second storage module configured to measure the batteryinformation of the second battery block.

In an embodiment, the isolating unit enables wireless power transferbetween the first communication unit and the first controller to powerthe first controller and between the second communication unit and thesecond controller to power the second controller. In an embodiment, eachof the first and second communication units are communicatively coupledto the managing unit via a first wire for bidirectional communicationand a second wire for power supply.

In an embodiment, each of the first and second isolating units includesa first antenna mounted on a first trace layer of a printed circuitboard and a second antenna mounted on a second trace layer of theprinted circuit board, the second antenna being directionally alignedwith the first antenna to enable the wireless information transferbetween the first and second antennas.

In a further embodiment, a power storage control apparatus includes abattery block comprising a plurality of battery cells, a controllerconfigured to measure battery information of the battery block, and anisolating unit that enables wireless communication with the controllerand wirelessly transmits power to the controller. In this furtherembodiment, the battery information includes one of a voltage value, acurrent value, or a temperature value. In this embodiment, the isolatingunit includes a first card unit and a second card unit being configuredfor a contactless smart card protocol to facilitate the wirelessinformation transfer, the first and second card units configured totransmit the battery information wirelessly to each other. Also in thisembodiment, the isolating unit may include a first antenna mounted on afirst trace layer of a printed circuit board and electrically connectedto the first card unit and a second antenna mounted on a second tracelayer of the printed circuit board and electrically connected to thesecond card unit, the second antenna being directionally aligned withthe first antenna to enable the wireless information transfer betweenthe first and second antennas.

In an embodiment, the power storage control apparatus further includes asecond battery block comprising a plurality of battery cells, whereinthe controller is additionally configured to measure battery informationof the second battery block. In an embodiment, the power storage controlapparatus further include a multiplexor communicatively coupled to thecontroller, the multiplexor configured to switch between the first andsecond battery blocks to enable the controller to measure batteryinformation of the first battery block separately from batteryinformation of the second battery block and an analog-to-digitalconverter communicatively coupled to the multiplexor and the controller,the analog-to-digital converter configured to convert analog dataassociated with the battery information of the first and second batteryblocks received via the multiplexor into corresponding digital data forthe controller.

In an embodiment, the controller is configured to actively balance avoltage level of the first and second the battery blocks. In anembodiment, the controller is configured to actively balance the voltageof the first and second the battery blocks by determining a differencebetween a charge potential of the first and second battery blocks andtransferring power from the battery block with a greater chargepotential to the battery block with a lower charge potential. In anembodiment, the isolating unit is configured to wirelessly provide powerto the controller, thereby enabling the controller to operateindependent of power stored in the battery block.

In yet another embodiment, a power storage apparatus to power a vehicleincludes a plurality of storage modules, each storage module includingat least one battery block comprising a plurality of battery cells, acontroller configured to measure battery information of the at least onebattery block, and an isolating unit that enables wireless communicationwith the controller and wirelessly transmits power to the controller. Inthis embodiment, the power storage apparatus also includes an electricalload including an electronic transmission or a motor of a vehicle, theelectrical load receiving power from an aggregate of power from theplurality of storage modules.

In an embodiment, the battery information includes one of a voltagevalue, a current value, or a temperature value. In an embodiment, eachof the isolating units includes a first card unit and a second card unitbeing configured for a contactless smart card protocol to facilitate thewireless information transfer, the first and second card unitsconfigured to transmit the battery information wirelessly to each other.

In an embodiment, the power storage apparatus to power the vehiclefurther includes a managing unit configured to aggregate the batteryinformation and the power from the plurality of storage modules. In anembodiment, the managing unit is configured to actively balance voltagelevels of the plurality of storage modules while the electronictransmission or the motor is being used to drive the vehicle.

In an embodiment, the isolating unit is configured with a controllerarea network (CAN) communication protocol to facilitate the wirelessinformation transfer. In an embodiment, the managing unit is configuredto communicate the aggregated battery information with other processorsin the vehicle via the CAN communication protocol.

Application in the Form of Home Power Storage System

An example of applying the disclosure to a home power storage systemwill now be described with reference to FIG. 33. For example, in thestorage system 100 of a house 101, power is supplied from centralizedpower systems 102 such as fossil-fuel 102 a, nuclear 102 b, andhydroelectric 102 c to a storage apparatus 103 via a power grid 109, aninformation network 112, a smart meter 107, and a power hub 108, etc. Inaddition, power from an independent power source such as a homegenerator 104 is supplied to the storage apparatus 103. Power suppliedto the storage apparatus 103 is stored. Power used in the house 101 issupplied by using the storage apparatus 103. The above is not limited toa house 101, and a similar power storage system may also be used for abuilding.

The house 101 is provided with the generator 104, power-consumingdevices 105, the storage apparatus 103, a control apparatus 110 thatcontrols the respective apparatus, a smart meter 107, and sensors 111that acquire various information. The respective apparatus are connectedby the power grid 109 and the information network 112. Solar cells, fuelcells, etc. may be used as the generator 104, with generated power beingsupplied to the power-consuming devices 105 and/or the storage apparatus103. The power-consuming devices 105 are a refrigerator 105 a, an airconditioner 105 b, a television receiver 105 c, and a water heater 105d, etc. Additionally, electric vehicles 106 are included among thepower-consuming devices 105. The electric vehicles 106 are an electriccar 106 a, a hybrid car 106 b, and an electric motorcycle 106 c.

For the storage apparatus 103, a battery unit of the disclosurediscussed earlier is applied. The storage apparatus 103 includessecondary batteries or capacitors, and may include a lithium-ionbattery, for example. The lithium-ion battery may be stationary or usedin the electric vehicles 106. The smart meter 107 is provided withfunctions for measuring commercial power usage and transmitting themeasured usage to a power company. The power grid 109 may involve one ofDC power transmission, AC power transmission, or wireless powertransmission, or a combination of a plurality of the above.

The various sensors 111 are a motion sensor, illumination sensor, objectsensor, power consumption sensor, vibration sensor, contact sensor,temperature sensor, and infrared sensor, etc. Information acquired bythe various sensors 111 is transmitted to the control apparatus 110.With information from the sensors 111, the state of the weather,persons, etc. can be ascertained to automatically control thepower-consuming devices 105 and minimize energy consumption.Additionally, the control apparatus 110 is able to externally transmitinformation regarding the house 101 to a power company, etc. via theInternet.

Processes such as power line routing and AC/DC conversion are conductedby the power hub 108. Methods of communication on the informationnetwork 112 to which the control apparatus 110 is connected includemethods that use a communication interface such as UART (UniversalAsynchronous Receiver-Transmitter), and methods that utilize a sensornetwork according to a wireless communication protocol such as Bluetooth(registered trademark), ZigBee, or Wi-Fi. The Bluetooth protocol isapplied to multimedia communication and is able to communicate onone-to-many connections. ZigBee uses the physical layer of IEEE(Institute of Electrical and Electronics Engineers) 802.15.4. IEEE802.15.4 is the name of a standard for short-range wireless networkscalled PANs (Personal Area Networks) or WPANs (Wireless PANs).

The control apparatus 110 is connected to an external server 113. Theserver 113 may be managed by the house 101, a power company, or aservice provider. Information transmitted and received by the server 113may be power consumption information, lifestyle pattern information,power rates, weather information, disaster information, and informationregarding power exchanges. Such information may be transmitted andreceived by a power-consuming device within the home (the television,for example), or by a device outside the home (such as a mobile phone,for example). Such information may also be displayed on a device withdisplay functions, such as a television, mobile phone, or PDA (PersonalDigital Assistant), for example.

The control apparatus 110 that controls the respective units is composedof a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM(Read-Only Memory), etc., and is housed inside the storage apparatus 103in this example. The control apparatus 110 is connected to the storageapparatus 103, the home generator 104, the power-consuming devices 105,the various sensors 111, and the server 113 by the information network112, and has functions for adjusting the amounts of commercial powerusage and power generation, for example. However, the control apparatus110 may also be provided with other functions besides the above, such asfunctions for exchanging power on an electricity market.

As above, power from not only centralized power systems 102 such asfossil-fuel 102 a, nuclear 102 b, and hydroelectric 102 c but alsogenerated power from a home generator 104 (solar power, wind power) canbe stored in the storage apparatus 103. Consequently, the amount ofpower sent out externally can be kept constant even if there arefluctuations in the generated power from the home generator 104, oralternatively, it can be controlled such that power is discharged ifnecessary. For example, one possible usage scenario may involve storingpower obtained by solar power in the storage apparatus 103 while alsostoring nighttime power in the storage apparatus 103 at night when ratesare lower, and discharging power stored by the storage apparatus 103during the daytime when rates are higher.

Also note that while in this example the control apparatus 110 isdescribed as being housed inside the storage apparatus 103, it may alsobe housed inside the smart meter 107 or have a standalone configuration.Furthermore, the storage system 100 may also be used with respect to aplurality of homes in a housing complex, and may also be used withrespect to a plurality of detached homes.

Application in the Form of Vehicular Power Storage System

An example of applying the disclosure to a vehicular power storagesystem will now be described with reference to FIG. 34. FIG. 34schematically illustrates an exemplary configuration of a hybrid vehicleimplementing a series hybrid system to which the disclosure has beenapplied. A series hybrid system is a vehicle running on an electrictransmission that uses power generated by a generator driving an engine,or power that has been temporarily stored in a battery.

On board the hybrid vehicle 200 are an engine 201, a generator 202, anelectric transmission 203, a drive wheel 204 a, a drive wheel 204 b, awheel 205 a, a wheel 205 b, a battery 208, a vehicle control apparatus209, various sensors 210, and a charge port 211. The earlier-discussedbattery unit of the disclosure is applied as the battery 208.

The hybrid vehicle 200 runs by taking the electric transmission 203 asthe source of motive power. A motor is an example of the electrictransmission 203. The electric transmission 203 operates on power fromthe battery 208, with the torque of the electric transmission 203 beingtransmitted to the drive wheels 204 a and 204 b. Note that both DCmotors and AC motors may be applied as the electric transmission 203 byusing an appropriate number of DC-AC or AC-DC conversions. The varioussensors 210 control the number of engine revolutions via the vehiclecontrol apparatus 209 and control the position of a throttle valve notillustrated (throttle position). The various sensors 210 include avelocity sensor, acceleration sensor, engine revolution sensor, etc.

Torque from the engine 201 is imparted to the generator 202, and it ispossible to store power generated by the generator 202 due to the torquein the battery 208.

When the hybrid vehicle is made to decelerate by a control mechanism notillustrated, the resistance during the deceleration is added to theelectric transmission 203 as torque, and the regenerative powergenerated by the electric transmission 203 due to the torque is storedin the battery 208.

By connecting to a power source external to the hybrid vehicle, thebattery 208 is able to receive supplied power from the external powersource with the charge port 211 acting as inlet, and is also able tostore received power.

Although not illustrated, an information processing apparatus thatperforms information processing related to vehicle control on the basisof secondary battery-related information may also be provided. Such aninformation processing apparatus may be an information processingapparatus that displays the remaining battery charge level on the basisof information related to the remaining charge level of the battery, forexample.

Herein, the foregoing describes by way of example a series hybrid carrunning on a motor that uses power generated by a generator driven by anengine or power therefrom which has been temporarily stored in abattery. However, this disclosure is validly applicable to parallelhybrid cars that take the output of both an engine and a motor assources of motive power and appropriately switch usage among the threemodes of running on the engine only, running on the motor only, andrunning on the engine and the motor. Furthermore, this disclosure isvalidly applicable to electric vehicles, which run on the drive providedby a driving motor only, without using an engine.

Modifications

Although the foregoing describes specific embodiments of the disclosure,the foregoing embodiments are not limiting, and various modificationsbased on the technical ideas in this disclosure are possible. Forexample, the configurations, methods, processes, shapes, materials, andvalues, etc. given in the foregoing embodiments are merely examples, anddifferent configurations, methods, processes, shapes, materials, andvalues, etc. may be used as appropriate.

Moreover, it is possible to combine together the configurations,methods, processes, shapes, materials, and values, etc. of the foregoingembodiments insofar as such combinations do not depart from theprincipal matter of the disclosure.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The application is claimed as follows:
 1. A power storage apparatuscomprising: a plurality of battery blocks connected in series, eachbattery block comprising a plurality of battery cells; a controllerconfigured to measure battery information of the battery blocks andbalance voltages based on the battery information by first balancing thevoltages of the battery blocks independent of the plurality of thebattery cells and then balancing the voltages of the plurality ofbattery cells within the battery blocks; and an isolating unit thatenables wireless information transfer regarding the battery informationof the battery blocks.
 2. The power storage apparatus according to claim1, wherein the battery information includes one of a voltage value, acurrent value, or a temperature value.
 3. The power storage apparatusaccording to claim 1, wherein the isolating unit includes a first cardunit and a second card unit being configured for a contactless smartcard protocol to facilitate the wireless information transfer, the firstand second card units configured to transmit the battery informationwirelessly to each other.
 4. The power storage apparatus according toclaim 3, wherein the isolating unit includes: a first antenna mounted ona first trace layer of a printed circuit board and electricallyconnected to the first card unit; and a second antenna mounted on asecond trace layer of the printed circuit board and electricallyconnected to the second card unit, the second antenna beingdirectionally aligned with the first antenna to enable the wirelessinformation transfer of battery information between the first and secondantennas.
 5. The power storage apparatus according to claim 3, whereinthe contactless smart cart protocol includes Amplitude Shift Keying(ASK) modulation with a carrier wave frequency of about 13.56 MHz at aspeed between 212 kbps and 424 kbps, the carrier wave having anamplitude between 2 volts to 13 volts with a 10% degree of modulation.6. The power storage apparatus according to claim 3, wherein theisolating unit enables wireless communication with at least one of thebattery blocks via non-contact smart card technology by applyingAmplitude Shift Keying (ASK) modulation to a carrier wave frequencybetween 10 MHz and 20 MHz.
 7. The power storage apparatus according toclaim 1, wherein the isolating unit includes a controller area network(CAN) communication protocol to facilitate the wireless informationtransfer.
 8. The power storage apparatus according to claim 1, whereinwireless information transfer includes transfer via at least one ofelectromagnetic induction, magnetic resonance, or electromagneticradiation.
 9. The power storage apparatus according to claim 1, whereinthe controller is configured to balance a voltage of a first batteryblock with a voltage of a second battery block.
 10. The power storageapparatus according to claim 9, wherein the isolating unit enableswireless power transfer to power the controller.
 11. The power storageapparatus according to claim 1, wherein the isolating unit includes: afirst antenna mounted on a first trace layer of a printed circuit board;and a second antenna mounted on a second trace layer of the printedcircuit board, the second antenna being directionally aligned with thefirst antenna to enable the wireless information transfer of batteryinformation between the first and second antennas.
 12. The power storageapparatus according to claim 11, wherein the first and second antennasare shaped in linear coil patterns.
 13. The power storage apparatusaccording to claim 12, wherein the first and second antennas aremagnetically coupled through the printed circuit board.
 14. The powerstorage apparatus according to claim 11, wherein the second antenna isconnected in parallel to a resistor and a capacitor to filter thereceived battery information.
 15. The power storage apparatus accordingto claim 11, wherein the first trace layer is separated from the secondtrace layer by at least one insulation layer of the printed circuitboard.
 16. A power storage system comprising: a first storage moduleincluding: a first battery block comprising a first plurality of batterycells; and a first isolating unit that enables wireless informationtransfer regarding battery information of the first battery block; and asecond storage module including: a second battery block comprising asecond plurality of battery cells; and a second isolating unit thatenables wireless information transfer regarding battery information ofthe second battery block; wherein the battery information of the firststorage module is aggregated with the battery information from thesecond storage module to first balance a voltage of the first storagemodule with a voltage of the second storage module, and wherein thebattery information of at least one of the first and second storagemodules is then used to balance a voltage of at least one of the firstplurality of battery cells and the second plurality of battery cells.17. A power storage apparatus to power a vehicle comprising: a pluralityof storage modules, each storage module including: at least one batteryblock comprising a plurality of battery cells; a controller configuredto measure battery information of the at least one battery block and usethe battery information to first balance a voltage of the storage modulewith a voltage of another storage module and to then balance a voltageof the plurality of battery cells; and an isolating unit that enableswireless communication with the controller and wirelessly transmitspower to the controller; and an electrical load including an electronictransmission or a motor of a vehicle, the electrical load receivingpower from an aggregate of power from the plurality of storage modules.18. The power storage system according to claim 16, wherein the firststorage module and the second storage module are connected in series.19. The power storage system according to claim 16, wherein thecontroller is configured to use the battery information to balance thevoltage of the first storage module with the voltage of the secondstorage module and then to balance the voltages of each of the firstplurality of battery cells and the second plurality of battery cells.20. The power storage apparatus according to claim 17, wherein theplurality of storage modules are connected in series.
 21. The powerstorage apparatus according to claim 17, wherein the controller isconfigured to use the battery information to balance the voltage of thestorage module with the voltage of the other storage module and then tobalance the voltages of the plurality of battery cells within eachstorage module.
 22. The power storage apparatus according to claim 1,wherein the isolating unit enables the wireless information transfer ofthe battery information using about a 13.56 MHz band.
 23. The powerstorage system according to claim 16, wherein the first isolating unitand the second isolating unit enable the wireless information transferof the battery information using about a 13.56 MHz band.
 24. The powerstorage apparatus according to claim 17, wherein the isolating unitenables the wireless information transfer of the battery informationusing about a 13.56 MHz band.
 25. The power storage apparatus accordingto claim 1, wherein the controller balances the voltages of theplurality of battery cells within the each of the battery blocksindependently of the other blocks.
 26. The power storage systemaccording to claim 16, wherein the voltages of the first plurality ofbattery cells are balanced independently of the voltages of the secondplurality of battery cells.
 27. The power storage apparatus according toclaim 17, wherein the voltages of the plurality of battery cells arebalanced independently of the voltages of battery cells of the anotherstorage module.